Focusing mechanism for photographic cameras



Jan. 4, 1927. 1,613,353

R. KROEDEL FOCUSING MECHANISM FOR PHOTOGRAPHIC CAMERAS Filed July 13, 1925 K 9 n l^ A y ATTORNEYS.

Patented Jan. 4, 1927.

UNITED STATES pag.353

PATENT OFFICE.

ROBERT KROEDEL, F ROCHESTER, NEW' YORK, ASSIGNOR TO EASTIVIAN KODAK COM- PANY, 0F ROCHESTER, NEVI YORK, A CORPORATION OF NEW YORK.

FOCUSING MECHANISM FOR PHOTOGRAPHIC CAMERAS.

Application filed July 13, 1925.

rThis invention relates to photography and more particularly to photographic canieras. One object of the invention is to provide an improved focusing mechanism by which the camera objective may be moved to and from the focal plane of the camera. Another object of my invention is to provide a simple focusing device which will hold the camera parts in an adjusted posit-ion. Another object is to provide a focusing mechanism which may be easily adjusted so as to care for objectives of different focal lengths. Other objects will appear from the following specification, the novel features being pointed out in the claim at the end thereof.

ln the drawings wherein like reference characters denote like parts throughout;

Fig. 1 is a side elevation of a camera having focusing mechanism constructed in accordance with and embodying one form of my invention;

Fig. 2 is a fragmentary plan view on an enlarged scale of the focusing mechanism shown in Fig. 1 and Fig. 3 is a section on line 3 3 of Fig. 2.

By Way of illustration, Ihave shown my focusing mechanism as being used on a well known type of compact folding roll film camera. This camera broadly comprises a body portion 1 to which there is hinged the usual bed 2 which is supported in an open portion by means of bed braces 3. There is a molding leg 4 for supporting the camera upon a llat surface. On the relatively fxed bed 2, there is mounted a movable plate 5 which is adapted to form a runway or track for the lens carriage 6 which is operated through the finger grips 7. This lens carriage carries a yoke 8 which supports the front end 9 of t-he camera bellows and the camera shutter 1() which carries the ob jcctive.

The edges of the plate 5 are formed upwardly at to provide rails which are engaged by the lens carriage. The plate 5 also carries a plurality of slots (only one being shown) through which studs 15 carried by the bed 2 pass. This plate may, therefore, be moved upon these studs by the iliollowing mechanism.

A bracket 17 is allixed to the movable plate 5 and this bracket extends into a slot 1S cut in the nut 19. This nut is preferably rough- Seriai Ne. 43.304.

cned or serrated as shown at 29, so as to form a grip by which it may be turned. The nut 19 is carried upon a threaded member 2O which is lixedly attached to the upstanding ends 21 over a bracket 22. Obviously when the nut 19 is turned upon the screw 20 it carries with it the bracket 17 and the plate 5, so that the camera objective may be f0- cused.

1n ordei to care Yfor objectives of slightly different focal length, such as are met with in ordinary manufacturing conditions, the bracket is provided with a. plurality of slots through which screws 23 pass into the camera bed 2. It is, therefore, a simple matter to adjust the bracket to care for the focal length lens being used on the camera. The camera bed 2 is provided with a flange Ll2 on the sides, but this flange is out away as is shown at 32 on the end of the bed, so that t-he plate 5 with its associated parts may slide out beyond the end of the bed as is inldicated in dot and dash lines in Figure 2.

T he operation of a camera equipped with my improved focusing device is as follows: The camera bed 2 is opened and the camera front is drawn out by means of the finger grips 7 until the carriage comes to a'stop in the usual manner. This locks the lens carriage to the movable plate 5. It is common practice to place the stop in such a position that when the lens carriage is drawn out the objective is focused on infinity. To focus the camera for nearer objects, the operator merely turns the nut 19 by the knurling 29, so that the nut will move upon the threaded member 2O thus moving with the bracket 17 and plate 5, which moves freely upon the studs 15. As it is not possible to move the nut through the bracket, the camera will remain in any set or adjusted position, until the operator again moves the nut.

lVhile I have shown my invention applied to acompact type of roll film Viamera, it is equally useful for any type of camera, wherein a movable member must bc adjusted relatively to a fixed member for focusing the camera objective.

'vlaving thus described my invention` what l claim as new and desire to secure by Letters Patent is:

Tu a photographic camera including an objective, the combination with a bed, of a movably mounted plate carried by the bed,

mils supported by Jthe movably mounted pluie adapted to support n lens cul-ringe, lueuug for moving the pluie relative to the bed including u hreaded member having :1 slot hereu, a fixed Screw mounted on one relatively u'lovable part und a bracket on the other movable pmt adapted to engage Jthe slot in the movable uut, whereby the camera muy be oeused by turning the nut on the screw moving' the plate through the bracket. 10

Signed at Rochester, New York, l'his 9th (luy of July, 1925.

ROBERT KROEDEL. 

